Structural highlights
Function
DUR3_ARATH High-affinity urea-proton symporter involved in the active transport of urea across the plasma membrane into root cells. May play an important role in urea uptake by plant cells at low external urea concentrations.[1] [2]
Publication Abstract from PubMed
Urea is a primary nitrogen source used as fertilizer in agricultural plant production and a crucial nitrogen metabolite in plants, playing an essential role in modern agriculture. In plants, DUR3 is a proton-driven high-affinity urea transporter located on the plasma membrane. It not only absorbs external low-concentration urea as a nutrient but also facilitates nitrogen transfer by recovering urea from senescent leaves. Despite its importance, the high-affinity urea transport mechanism in plants remains insufficiently understood. In this study, we determine the structures of Arabidopsis thaliana DUR3 in two different conformations: the inward-facing open state of the apo structure and the occluded urea-bound state, with overall resolutions of 2.8 A and 3.0 A, respectively. By comparing these structures and analyzing their functional characteristics, we elucidated how urea molecules are specifically recognized. In the urea-bound structure, we identified key titratable amino acid residues and proposed a model for proton involvement in urea transport based on structural and functional data. This study enhances our understanding of proton-driven urea transport mechanisms in DUR3.
Structural basis of urea transport by Arabidopsis thaliana DUR3.,An W, Gao Y, Liu L, Bai Q, Zhao J, Zhao Y, Zhang XC Nat Commun. 2025 Feb 20;16(1):1782. doi: 10.1038/s41467-025-56943-2. PMID:39972035[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Liu LH, Ludewig U, Frommer WB, von Wirén N. AtDUR3 encodes a new type of high-affinity urea/H+ symporter in Arabidopsis. Plant Cell. 2003 Mar;15(3):790-800. PMID:12615950 doi:10.1105/tpc.007120
- ↑ Kojima S, Bohner A, Gassert B, Yuan L, von Wirén N. AtDUR3 represents the major transporter for high-affinity urea transport across the plasma membrane of nitrogen-deficient Arabidopsis roots. Plant J. 2007 Oct;52(1):30-40. PMID:17672841 doi:10.1111/j.1365-313X.2007.03223.x
- ↑ An W, Gao Y, Liu L, Bai Q, Zhao J, Zhao Y, Zhang XC. Structural basis of urea transport by Arabidopsis thaliana DUR3. Nat Commun. 2025 Feb 20;16(1):1782. PMID:39972035 doi:10.1038/s41467-025-56943-2
